Tiled projection systems can deliver very high resolution, but it is difficult to hide the seams separating tiles, and output is often reduced to produce uniform tiles. For applications where large pixel counts are desired, such as command and control, tiled projection systems are a common choice. However, registration, color, and brightness must be carefully controlled in a tiled projection system. Matching color and brightness is accomplished by attenuating output, which costs lumens.
Redundancy can be provided in tiled projection systems by aligning images from two or more projectors at the same place on a screen. Consequently, if one projector fails, the other operative projector(s) is still projecting that portion of the overall tiled image. However, the luminance of that portion will be lower than the rest of the tiled image, causing a distraction for the viewer. This is a challenging problem for tiled projection systems.